Homeless adults have disproportionate rates of drug use disorders, especially those dually diagnosed with other mental disorders. Drug use disorders are significantly associated with homelessness, early onset of homelessness, protracted homelessness, and housing instability. However, the homeless population does not fully utilize drug abuse treatment. Previous research has identified family involvement as an important predictor of treatment outcomes and housing among homeless populations. A variety of educational group intervention models for families have demonstrated effectiveness. An experienced, multidisciplinary research team in social science and medicine will develop a family-based intervention against drug abuse, pilot this intervention, and develop methods that can be used to evaluate the success of this intervention. This project strives to apply research to practice in order to reduce and reverse adverse consequences of drug abuse and homelessness. The proposed intervention, empowering families as partners against drug abuse, is based on responsive educational groups for relatives of persons who are homeless and abusing drugs. This project will develop educational groups for 25 family pairs, one homeless person meeting diagnostic criteria for drug abuse disorder and one close relative, helping families engage their drug abusing relatives in treatment and recovery. This project will test methods for assessing intervention outcomes, surveying both homeless individuals and their relatives before and after they attend multifamily groups. For homeless drug abusers, this project will measure primary outcomes, including severity of drug use disorder, housing status, and use of health and social services. For relatives, this project will measure secondary problems related to drug abuse, including family burdens, social support, social costs, health and social service use. This study will contribute to our knowledge of recovery from drug abuse in homeless populations, which can be improved by a strong and supported family.